Alidade or indicator for ships&#39; compasses.



No. 731,151. 7 PATENTED JUNE 23, 1903. W. S; BURGESS.

ALIDADB 0R. INDICATOR FOR SHIPS GOMPASSES.

APPLICATION FILED JULY 12. 1902.

I0 IQDEL. 2 SHBETS-SHEET 1- 1 wnmmmmmu JBQQWL J M No. 731,751 PATENTEDJUNE 23,1903. W; s. BURGESS.

ALIDAD EOR INDICATOR. FOR SHIPS GOMPASSBS.

APPISIOATIOR FILED JULY 12, 1902.

110 MODEL. 2 SHEETS-SHEET 2.

"Mill a UNITED STATES 1 PATENT Patented June 23, 1903.

OFFICE.

ALIDADE OR INDICATOR FOR SHIPS COMPASSES.

SPECIFICATION forming part of Letters Patent No. 731,751,

dated June 23, 1903.

Application filed July 12, 1902. Serial No. 115 ,306. \No model.)

To all whom it may concern.-

Be it known that 1, WILLIAM S. BURGESS,

a citizen of the United States, and a resident of Boston, county ofSuffolk, and State of Massachusetts, have invented an Improvement inAlidades or Indicators for Ships Oompasses, of which the followingdescription, in connection with the accompanying drawings,

is a specification, like letters and numerals on the drawingsrepresenting like parts.

This invention has for its object the production of a highly efficientand accurate alidade or indicator of novel construction for thecompasses of sea-going vessels, whereby at all times the bearings of anobject distant from the vessel may be readily taken and simultaneouslyand with great accuracy indicated on the face of the compass-dial.

In my present invention the sighting device is rotatably mounted on thebinn'acle, while the alidade orindicating-pointer is carried wholly bythecompass and is angularly movable adjacent the dial thereof, andinasmuch as the compass is maintained substantially level at all times,while the binnacle partakes of the motion of the vessel, a connectionbetween the sighting device and alidade is provided which maintains themalways in the same radial plane and angularly movable in unison, whilepermitting a relative tipping movement of the sighting device andalidade in such plane.

The variousnovel features of my invention will be hereinafter described,and particularly pointed out in the following claims.

Figure 1 shows in vertical section a ships binnacle with its pedestalorstand broken off,

' the compass being shown in elevation with one embodiment of myinvention applied thereto. Fig. 2 is an enlarged sectional detail on theline 2 2, Fig. 1, showing the manner in which the alidade is supportedand a portion of the universal joint between it and the shaft on whichthe sighting device is mounted. Fig. 3 is an enlarged detail, in frontelevation and partly broken out,

of the connecting member between the alidade and the shaft. on which thesighting device is mounted, the alidade being also shown with a portionof the joint attached thereto broken out. Fig. 4 is a side elevation,en-

larged, of the parts shown in Fig. 3. Fig. 5

is an enlarged perspective view of the indicating device as a wholedetached from binnacle and compass, and Figs. 6 and 7are sectionaldetails of modified means for supporting the alidade on the compass tobe described.

As will appear more fully hereinafter, my novel alidade or indicatingdevice can be readily applied to existing binnacles and their compassesin a thoroughly clficient manner, or it may be applied during theconstruction of the binnacle.

Referring to Fig. 1, the binnacle frame or case A, of any desirable orordinary construction, is provided with windows A for the admission oflight and observation of the compass 0, suspended in usual manner in thebowl-like base A of the binnacle, so that its dial is horizontal and theattached magnetic u needle always points to the north, the usual inaftercalled the alidade and best shown in Figs. 3, 4., and 5, is rotatablymounted on the compass and movable adjacent the dial thereof just abovethe plate 0, and in Figs. 1 and 2 I have shown one very efficient meansfor supporting the alidade. A small disk (Z, preferably of glass, has acentral upright metal pin or stud (1 secured firmly to it, and the diskis cemented to the upper surface of the glass plate 0 of the compass,the stud d being located at the center of the plate directly over thecenter of the compass-dial. The pin or stud d projects some littledistance above the plate a and forms a bearing upon which the alidade Dis rotatably mounted, and referring to Fig. 2 the alidade has rigidlysecured to it an upright post d at right angles to it and in alinementwith the center of the alidade, the latter havin-ga central hole (1 toreceive the reduced end 01 of the post, the latter having a longitudinalhole (:1 therein to receive the bearing-pin or stud CF. The upper end ofthe post is enlarged in diameter and provided with a longitudinal bore(Z and the bored part of the post is longitudinally slotted from itsupper end down to the bottom of the bore at d", Figs. 2, 8, 4, and 5.The slots (1 are diametrically opposite each other, and such diameter isat right ICO angles to the length of the alidade D, the post constructedas described constituting one part or member of a universal-jointconnection between the alidade and the shaft upon which the sightingdevice is mounted.

The top a of the binnacle is provided with a central hole to receive thelower end of an upright rotatable shaft, carrying atits upper end asuitable sighting device and at its lower end connected with the alidadeby a universal-joint connection of peculiar and novel construction, tobe described. The shaft comprises three sections, as herein shownatubular main section b, longitudinally slotted at b, an upper tubularend section 17 slidably mounted within it and held from rotation by afin b entering the slot b, (see Figs. 1 and 5,) and a lower end section5*. A clamp or setserew b in the opposite ears 4 at the upper end of themain section serves to maintain the section b in longitudinally-adjustedposition, and the sections b and b are connected and also held fromrelative rotative movement by a suitable screw 5 mounted in the formerand adapted to enter a socket 5 in the latter. (See Fig. 1.) At itsupper end the section b is longitudinally slotted in the plane of theslot 1) to present parallel upturned ears 5 between which enters adepending lug e fast on the sighting device E, shown as a bar havingalined hinged sights e at its ends, a clamp-screw 6 passing through theears b and lug e constituting a fulcrum on which the sighting device canbe tipped when in use, said fulcrum being at right angles to the deviceE and also to the ears Any suitable sighting device, such as atelescope, may be used instead of the sightingbar shown, the particularstructure thereof being immaterial so far as my present invention isconcerned.

By loosening the set-screw b the shaft-section 12 can be raised orlowered, as desired,

in the section b to thereby bring the sighting device to a levelconvenient for use by the observer and then clamped, while the plane inwhich the device E can tip will always intersect the longitudinal axisof the sectional shaft and maintain a fixed radial position relativethereto.

The section b is reduced in diameter at its lower portion to form ashoulder 6, and the reduced portion has mounted upon it anexternally-threaded sleeve 7,having an enlarged flat circular flange orhead 8, adapted to rest upon the binnacle-top a said flange abuttingagainst the shoulder 6, and thereby vertically supporting the sectionalshaft, the sleeve passing down through the hole in the binnacle-top andbeing rigidlyclam ped thereto by a nut 9 on the threaded portion of thesleeve, as shown clearly in Fig. 1, the foot of the shaft-section bpassing down through the sleeve into the binnacle. The nut 9 when set upbears against the under side of the cle and providing a long firmbearing in which it can rotate.

The end section b is longitudinally bored to receive a rod-likeextension 10, herein shown as having a longitudinal groove 12, enteredby a feather 13 on the section b to prevent rotation of the extension,longitudinal movement thereof being prevented by a suitable set-screw14, Fig. 1.

By the longitudinal adjustment of the extension 10 I provide theapparatus for binnacles of different heights, the distance between thedial of the compass and the binnacle-top 0t varying very considerably indifferent structures.

The lower end of the extension 10 has rigidly secured to it a cross-bar15, parallel to the fulcrum e on which the sighting device E rocks, thedescribed connections between the several parts of the sectional shaftabsolutely preventing their relative rotation, and consequently alwaysmaintaining the said fulcrum and cross-bar in the same plane and onewhich intersects the longitudinal axis of the shaft.

A downturned yoke 11 having upturned ears If, is pivotally connectedwith the crossbar by pointed pivot-screws b (see Fig. 3,) extendedthrough the ears and seating in concavities 16 in the opposite ends ofthe crossbar, suitable set-screws 11 holding the pivotscrews immovablein the ears, the pivotscrews providing for taking up wear. The yoke canthus rock or swing fore and aft relatively to the sighting device, buthas no movement in a transverse direction relatively to the uprightshaft, the downturned ends of the yoke being provided with parallel hubsb Figs. 4 and 5, at right angles to the pivotscrews Z9 the opposite endsof the hubs having depressions 17 therein (see dotted lines, Fig. 4) fora purpose to be described.

An open extension member of peculiar construction, now to be described,completes the connection between the upright sectional shaft and thealidade, so constructed and arranged that whatever the rolling,pitching, or other movements of the vessel the alidade D will moveangularly in unison with the sighting device when the latter is turnedupon its upright support-viz., the sectional shaft and in a planeintersecting the longitudinal axes of the alidade and sighting device,respectively. The extension member comprises, as herein shown, two likeXshaped upright sides F, provided at the upper and lower open orbifurcated ends thereof with pairs of opposite inturned pivot-screws ff,respectively, the former being held in adjusted position by set-screws18, and having their inner ends pointed to enter the depressions 17 inthe opposite ends of the hubs b. One side F is thereby pivotallyconnected at its upper end with each hub, the sides being adapted toswing transversely to the sighting device.

The pair of pivot-screws f at the lower end of each side of theextension member are held in place by set-screws 20 and are also inturned-and opposed, their inner ends being pointed to enter depressions19, Fig. 4, in the opposite ends of short arms f rigidly secured to theends of a cross-bar f at right angles thereto, and consequently parallelto each other, the arms being so placed that the distance between thecenters of the two pairs of pivot-screws f is exactly equal to thatbetween the pivot-screws f. Consequently the sides F will always remainin parallelism, and b the cross-bars 15 and f will also be maintained inparallelism under all circumstances.

It is to be observed, however, that the crossbarf which forms the footof the extension member, can swing fore and aft relatively to thesighting device about the pivot-screws I) as fulcra, and it can alsomove longitudinallyin a direction transverse to the sighting device, butalways in parallelism with its fulcrum 6 At its center the bar or foot fhas a ball-like enlargement f which fits freely in the bore 01 of theupturned post d of the alidade, the upright slots (1 receiving the .barat each side of the enlargement, as will be clearly understood from thedrawings. The bar or foot f of the extension member may thus rise andfall in the slotted foot,

device is swung to take a sight, will be transmitted simultaneously andequally to the alidade by the cooperation of the bar f and the slottedpost d", the rod or extension 10 being so adjusted that under allconditions the connection at the part f will be maintained.

By the construction described a universaljoint connection is thusinterposed between and connects the lower end of the upright shaft andthe alidade, the connection being self-adjusting for all movements ofthe binnacle relatively to the compass-dial, whichremains substantiallyhorizontal.

It will be manifest from the foregoing description that the longitudinalaxes of the alidade and the sighting device will always be maintained inthe-same radial plane and compelled to move angularly in unison, no

matter what maybe the inclination of the upright shaft relative to theplane of the comserved.

pass-dial, so that under all conditions of pitching, rolling, or.vibrations of the Vessel the universal and self-adjusting connectionbetween sighting device and alidade will be pre While they aremaintainedin the same radial plane, it will be obvious that relative tipping ofthe sighting device and alidade in such plane is permitted by theconnection between them, so that in taking bearings the sighting devicecan be tipped on its fulcrum e as may be necessary or desirable.

The extension member by reason of its separated sides F and the distancebetween the yoke 01 and the cross-bar f presents asightopening, throughwhich a free and unobstructed view of the lubber-mark and alidade isafforded, and instead of making the sides F straight they may be bentorbowed outward, if desired, to increase the sight-opening.

The alidade being movable close to the compass-dial, the reading of abearing observed by the aid of thesighting device is made very accurate.

In order to apply the apparatus to a binnaale and compass, it is onlynecessary to make the shaft-hole in the top of the former connect thebearing-sleeve 7 therewith and insert the lower end section b of theshaft and fix therein the extension-rod 10, as described, and mount thealidade on the compass.

In Fig. 6 I have shown means for supporting the alidade, which is amodification of the means shown in Figs. 1, 2, and 5, the alidade D andthe upper end of the post cl being bored and slotted substantially ashereinbefore described; but the lower end of the post is extended andreduced in diameter to form an annular shoulder (1 which rests on thetop of the glass cover a of the compass, and a pin d, which rotatablyenters a hole in said cover. Thus the alidade is directly supported in arotatable manner by the cover 0.

Yet another modification of the alidadesupporting means is shown in Fig.7, wherein I employ a split ring c having an internal annular groove 0to receive the periphery of a circular plate 0 of glass, the ring 0being set down into the holding-ring 0 so that there is a space betweenthe plate 0 and the glass cover a. The plate 0 has secured to it at itscenter an upturned sleeve 0, preferably of metal, and the lower end ofthe post (1 is reduced in diameter and elongated, as at (Z to enter thesleeve and project below it, the

d on the post rests on the top of the sleeve 0 and is thereby verticallysustained. In this construction the alidade is protected by thesuperposed plate 0 The connection between the alidade and the sightingdevice is that hereinbefore described whatever the mode of supportingthe alidade on the compass, and whatever the manner of supporting thealidadethere will be no obstruction to a clear viewof its extremities.

I have herein shown and described one practical embodiment ofmyinvention' as a Whole and several different forms of supporting meansfor the alidade, and my invention accordingly is not restricted to theprecise construction and arrangement herein shown and described, as thesame may be modified. or changed in various particulars or detailswithout departing from'the spirit and scope of my invention.

Having fully described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. A binnacle, a compass therein, an alidade or indicator mounted on andpositively connected with the compass and rotatable adjacent the dialthereof, an upright shaft rotatably mounted on and extended above thetop of the binnacle and having a sighting device at its upper end, and aconnection between said shaft and the alidade or indicator to maintainit and the sighting device in the i same radial plane and permitrelative tipping movement of the alidade and sighting device in suchplane.

2. A binnacle, a compass therein,-a central support fixedly mounted onthe compass, an alidade or indicator rotatable on said support adjacentthe compass-dial, an upright rotatable shaft centrally mounted on thebinnacle and having a sighting device at its upper end, and a connectionbetween the lower end of the shaft and the alidade or indicator, tomaintain it and the sighting device angularly movable in the same planeand permit relative tipping movement of the. alidade and sighting devicein such plane.

3. A binnacle, a compass therein, a support fixedly mounted on thecompass, coaxial with the needle, an alidade or pointer rotatable onsaid support, adjacent the compass-dial, a sighting device rotatablymounted on the binnacle, and connecting means between said device andthe alidade or pointer to maintain them in the same radial plane andpermit relative tipping movement of the sighting device and alidade insuch plane.

4. A binnacle, a compass therein, a support fixedly mounted on thecompass at the center of the dial, an alidade or pointer rotatable onsaid support adjacent the dial, an upright shaft rotatably mounted onthe binnacle, a sighting device mounted to tip on the upper end of theshaft in a plane intersecting the longitudinal axis of the latter, and aconnection between the lower end of the shaft and the alidade orpointer, to maintain it and the sighting device in the same radial planeand permit relative tipping movement of the sighting device and alidadein such plane.

5. In an alidade for ships compasses, a rotatablevertical shaftsupported centrally in the binnacle-top, a sighting device pivotallymounted on the upper end of the shaft to tip in a plane intersecting thelongitudinal axis of the shaft, an alidade or pointer, a bearing onwhich it is rotatably mounted adjacent the compass-dial, means torigidly sustain said bearing on the compass at the center of the dial,and a connection between the lower end of the rotatable shaft and thealidade or pointer, to maintain the latter and the sighting device inthe same radial plane and permit relative tipping movement of saidsighting device and the alidade in such plane.

6. In an adjustable alidade for ships com passes, a rotatable,longitudinally-extensible shaft supported centrally in and extendedabove and below the binnacle-top, a sighting device on the upper end ofthe shaft, an alidade or pointer rotatable adjacent the compass-dial, acentral bearing for the alidade, 1 fixedly mounted on the compass, and acon- 'nection between the lower end of the shaft and the alidade, tomaintain the latter and the sighting device in the same radial plane andpermit relative tipping movement of said device and the alidade in suchplane.

7. A binnacle and its compass, an alidadesupport fixedly mounted on thecompass centrally of the dial, an alidade or pointer rotatably mountedon said support adjacent the dial, an upright shaft centrally androtatably mounted in the binnacle-top and having a sighting device atits upper end, and a connection between the lower end of the shaft andthe alidade to maintain it and the sighting device in the same radialplane and permit relative tipping movement of the alidade and sightingdevice in such plane, said connection including a member having asightopening aifordiug a clear view of the alidade and the lubber-markwithin the binnacle.

8. A binnacle, a rotatable, upright, longitudinally-extensible,sectional shaft mounted in the top thereof and having on its upper end asighting device, a transverse fulcrum on which the latter may tip, thecompass mounted within the binnacle, a central bearing above thecompass-dial, an alidade or pointer rotatably mounted on the bearing andangularly movable adjacent the dial, a fixed cross-bar on the lower endof the shaft, parallel to the fulcrum of the sighting device, and auniversal connection between the crossbar and the alidade, to maintainthe latter and the sighting device in the same radial plane and permitrelative tipping movement of the alidade and sighting device in suchplane.

9. A binnacle, a rotatable, upright shaft mounted in the top thereof andhaving on its upper end a sighting device, the compass mounted withinthe binnacle, a bearing above the center of the compass-dial and fixedlymounted on the compass,an alidade or pointer rotatably mounted on saidbearing and angularly movable adjacent the dial, and a connectionbetween the lower end of the shaft and the alidade to maintain it andthe sighting device in the same radial plane while permitting them totip relativelyin such plane, said connection including a memberuniversally jointed to the shaft and having its depending sideslaterally separated to constitute a sight-opening.

10. A binnacle, a compass therein, a bearing fixedly mounted on thecompass at the center of the dial, an alidade or pointer rotatable onsaid bearing adjacent the dial, an upright rotatable shaft mountedcentrally in the binnacle-top and having a sighting dej p of, anupturned, longitudinally-bored post vice at its upper end,alongitudinally-adjust- 1 able rod mounted in the lower end of the shaftthereto, and a sliding, ball-and-socket connection between the lower endof said memher and the alidade, to maintain the latter and the sightingdevice in the same radial plane and permit relative tipping movement insuch plane.

11. A binnacle, a compass therein, an alidade or pointer rotatablymounted on thecompass and movable adjacent the dial there-.

rigidly secured to the center of the alidade and having oppositelongitudinal slots, a shaft rotatably mounted in the binnacle-top andhaving a sightingdevice mounted on its upper end, and a dependingextension member fnlcrumed on the lower end of the shaft to swingtransversely to and also longitudinally of the sighting device andcomprising -two separated sides, and a foot or cross-bar con meeting thelower ends of the sides, and a ball-like enlargement central on thecrossbar, to enter the bore of the post, the slots of the latterreceiving the cross-bar and maintaining it transversely to the alidade,the de- 1 scribed connection between the sighting device and alidademaintaining them angularly movable in unison in the same radial planeand permitting relative tipping movement thereof in such plane.

12. binnacle, a compass therein, an alidade or pointer angularly movableadjacent the compass-dial, a bearing rigidly connected with the compassand on which the alidade is rotatably mounted, an upright shaftcentrally and rotatably mounted,'in the binnacle-top and having asighting device at its upper end, and a universal-joint, tippingconnection between the shaft and the alidade, to permit irregularmovement of the shaft relative to the compass-dial and maintain thesighting device and alidade angularly movable in the same radial plane.

13. In an alidade or indicator for ships compasses, the compass, itscover-plate, an upright bearing rigidly secured to the center thereof,an alidade pivotally mounted on said bearing to move angularly above thecoverplate, an. upright, rotatable shaft, a sighting device mounted onthe upper end thereof, a

sleeve-bearing for said shaft, adapted to be secured to thebinnacle-top, a rod adjustable longitudinally in the lower end of theshaft and extended into the binnacle, and a universal,longitudinally-extensible connection between said rod and the alidade,maintaining it and the sighting device angularly' movable in unison andpermitting tipping movement of the sighting device relatively to thealidade.

14:. A binnacle, a compass therein, an alidade or pointer angularlymovable adjacent the compass-dial, a bearing rigidly connected with thecompass and on which the alidade is rotatably mounted, an upright shaftcentrally and rotatably mounted, in the binnacle-top and having asighting device at its upper end, a yoke pivotally connected with thelower end of the shaft within the binnacle, to swing fore and aft of thesighting device and having transverse, parallel hubs at its ends, an extension member comprising sides pivoted at their upper ends to the endsof the hubs, to swing transversely of the yoke, a cross-bar or foothaving transverse, parallel arms at its ends, pivotal connectionsbetween the ends of the arms and the lower ends of the sides, wherebythe latter are maintained in parallelism, the cross-bar being maintainedparallel to the yoke, and a ball-and-socket, sliding connection betweenthe cross-bar at its center and the alidade, substantially as and forthe purpose described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

WILLIAM S. BURGESS.

Witnesses:

GEO. W. GREGORY, MARGARET A. DUNN.

